Feldemission

Field Emission from Graphene Nanosheets

“…The insets in the figure indicate the typical patterns that were observed for each molecule. As was observed in GNS, the same two-lobed, four-lobed, circle and ring patterns were observed in both organic molecules, especially clearly observed in Cu-Pc (Müller, 1953). The FEM images of these molecules, representing far field pattern of electron wave, show the same symmetrical patterns as those observed in GNS structures.…”

“…Figure 14 shows the experimentally observed symmetrical Quantitative discussion related with the magnitude of the energy difference for the different quantum number is necessary to be clarified; however, qualitatively, adsorbed or desorbed atoms on and off  conjugated ring cavity (emission sites) would change the energy level of the cavity modes, thus the patterns rotate discontinuously and change reversibly. We note here, the quantum number n is degenerated; however, when the degeneracy is solved by the existence of a magnetic moment and/or a localized spin near the  conjugated cylindrical cavity, we can expect topologically interesting patterns such as an entangled pattern of electron wave function for FEM measurements (Müller, 1953;Ashworth, 1951;Dyke & Dolan, 1956;Becker, 1955). The mystery of the same topological patterns between FIM and FEM were clearly solved by considering the phase of the electron wave function for both FIM and FEM patterns, and quantitatively analyzed by using the electron wave optics.…”

“…We show that each emission site of GNS creates many beautiful symmetrical patterns. These symmetrical patterns are known as cloverleaf patterns of organic molecules and the origin of the cloverleaf patterns has been discussed more than 60 years; however, this is still open question (Müller, 1953;Ashworth, 1951;Dyke & Dolan, 1956;Becker, 1955;Wolf, 1955;Dean, 2002). In order to solve this difficult problem, we try to reproduce the same cloverleaf patterns by using historically used organic molecules such as phthalocyanine and pentacene.…”

Mapping the field-emission tunneling barrier of organic adsorbates on tungsten

“…Unfortunately, repeated dosings and cleanings of the emitter with field applied resulted in surface carbon contamination and significant ''build up'' of the edges of the close-packed planes. 1,21 This complicates our observations because of the presence of unknown organic adsorbates, probably thermal decomposition products of CuPc, on the surface. Furthermore, since most small organic adsorbates produce identical FEEM images, 22 it is impossible to determine the exact source of the images within the limitations of the FEEM.…”

Point‐projection imaging of macromolecular contours

“…For the past 30 years, attempts have been made to use the field-electron emission microscope (FEEM) and the field-ion microscope (FIM) to image organic molecules (Miiller, 1950a(Miiller, , by 1953aMelmed, 1958;Melmed & Miiller, 1958;Gurney et al, 1965;Miiller & Rendulic, 1967;Graham et al, 1973). These attempts were inspired by the simplicity of the techniques and the potential for achieving high image contrast, magnification and resolution.…”